CXCL1 and esophageal squamous cell carcinoma: This property of CXCL1 is dependent on extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) activation and decreased superoxide dismutase 1 (SOD-1) expression, which leads to an increase in the level of reactive oxygen species (ROS) in ESCC cells which increases the expression of DNA repair enzymes when cells are exposed to radiation therapy [56].